Process for manufacturing oxalates.



LAUNCELOT W. ANDREWS, OF CHICAGO, ILLINOIS.

PROCESS FOR MANUFACTURING OXALATES,

No Drawing.

To all whom it may concern;

Be it knoivn that I, llavsiuno'r W. Axonntvs, a citizen of the UnitedStates, and a. resident of Chicago, (Took county, and State. ofIllinois, have invented certain new and. useful Improvements inProcesses for h'lauutacturing ()xalates, of which the following is aspecification.

'lhe im'ention relates to the manufacture of alkali oxalates from alkalifol-mates. .\s is well known, sodium or other alkali lor mate isconverted into oxalate by the at'tion of heat, \vherehy hydrogen gas isliberated and alkali oxalate produced. It is the present practice to addto the sodium (or other alkali) formate used, large amounts of inertsubstances such as sodium carbonate,

sodium oxalate, charcoal powder. etc. or small amounts of tree alkali,i. (a, sodium hydroxid, NaOH, or potassium h vdroxid. KOII. The ohjeetof these additions is to increase the. yield otoxalate. and to securebetter regulation and control of the reaetion.

The present invention is based on the dis-- eovery of the fact that anadmixture'ol" a small amount of a suitable phosphate, preterahly sodiumor potassiumphosphate, to the formate employed in the pt'nt'tss, has ahighly la-uelicial intluem-e. in that ll inrreases the vield of oxalate,renders the reartion less storn'iy, sudden, turbulent or explosive andmore easily controlled, and avoids the introduction of large amounts offoreign material which musthe suhsequently separated from the product atconsiderable expense; lhe. recovery of the small amount of phos 'ihaterequired in the new procedure can he readily andinexpensively accent--plished.

Preferably, dior tri-alkali phosphate is employed. and.. in accordancewith the preferred procedure, disodituu" phosphate, Na lllo or trisodiumphospl'iate, Na ,I:O,, is used. The amount of alkali phosphate required'does not, exceed one or ttvo per rent. of the-weight. of the tornadoused. For

example, the improved process can he earried out as follows Example: 500pounds of sodium t'ormate, is intiluatoly mixed with T pounds ot tri-Specificatton of Letters Patent.

Patented Oct. 8. 11H 8.

Application filed May 8, 1915. Serial No. 26.740.

sodium phosphate, Xa,, l() which may coir tam water of crystallizationor may lie drv. The mixture is then heated to a suitahlc temperature.say about 380" t., until the reac tion is t'omplete. The art ionproceeds steadily and rapidly until near the end, when it lat-comessomewhat slower.

While the diand trisodium and potasslum phosphates are preferred and ranbe readily recovered from the alkali oxalate. produeed, the presentinvention contentplates as within its seope, the use of other solublephosphates which act as eatalvzers of the desired reat-tion and which donot contain bases which intert'ere with or not as autiratalyzers of thedesired'reartion. FLIT- thermore. the term phosphate" as herein used isto he understoodfunless otherwise qualified. as designating any chemicalcom pound eontainiing, the radicles characteristic of the various knownphosphoric acids. as for example, of otho phosphoric acid, H,- P0,), orpyro-phosphori acid, Hal-1,0,), or of meta phosphoric acid I-'[(P(),),and. it is recognized thatthe properties which make tl'lese(OllllJOtlHtlH suitable. for the purposes of the hereiu-deseritwd'tveuti-on are due mainly to these acid or negative groups and onlysuherdinately to the other elements present in the eompounlh Asrecognized ahove, however, certain phosphates ea'inot, he used toadvantage in the present.- improved proeess. These are the phosphates ofbases Whieh-dtlterfere with or act as antieatalyzers of the desiredreaction, as for example, the phosphates ol the soealled heavy metals.

' It is obvious that. changes may be made in-v the details set forthWithout departure front the essentials of the invention as defined inthe claims.

I claim as my invention 1. The process of manufacturing ()XtLItlQQQ byheating: a i'uixt-ure o't tot-mates and eatinl t'llt' phosphates.

2. The process of manufacturing alkali metal oxalates, which eonsists inheating alkali metal tormat'e. admixed with catalyttc phosphate. Theprocess of nianul'acttmug alkali mulizil oxnlnles, which culls" (18 inlimiting alkali metal formula admixed wit-l1. alkali nmlal. pllusplmlv.

4. The process of numul'awtu'ing alkali E nml'ul nit-(llama, whichconsists in limiting an alkali metal lfuriiiaw admixed with polylmsicalkali metal [)llOSplldle.

5. Thu ijl'fiflrrlh ul nn'ul'ufnuluring alkali metal (lXnllllA'I-l,wl'iii'li consists in limiting ullulli im-lzil .l'm'nmli: zulmixuilWilli u l'clzil0 llVQly small amount of pulylmsiu phosphate of u um'numnFlllnilli mul'ul.

LAUNQELOJ W. ANDREWS.

